1. Field of the Invention
The present invention relates to an optical disk reading device, and in particular, to a positioning device for use in an optical disk reading device that can receive and position disks of different sizes.
2. Description of the Prior Art
Conventional optical disk reading devices, such as compact disk players, typically have a disk support tray that controls the insertion, ejection and carriage of the disk. In this regard, conventional disks have all been provided in a standard 12 cm diameter (“12 cm disk”), but recent developments have led to the common use of disks having a smaller 8 cm diameter (“8 cm disk”).
In order for disks of both sizes to be used in the same compact disk player, it is necessary when positioning the disk on the disk support tray to make sure that the spindle table contacts the disk in a smooth operation. A rack is typically installed at the bottom of the disk support tray, and a motor drives a gear engaged with the rack to rotate the gear, causing the rack to move in and out while engaged with the gear. The disk support tray has a containing space for depositing a disk of 8 cm or 12 cm in diameter. However, while in use, it is impossible for a conventional compact disk player to know which type of disk the user is depositing. Therefore, the conventional compact disk player uses as its positioning basis the standard 12 cm disk. As a result, when an 8 cm disk is inserted, it may be difficult or impossible to properly position the disk, resulting in a read failure when it attempts to read an 8 cm disk. In other words, a conventional compact disk player is unable to detect the size differences between the disks, and does not have any mechanism that is adapted for doing so.
Thus, there remains a need for an optical disk reading device that can receive and read both 8 cm disks and 12 cm disks.